Append Files to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append files to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files to a pre-existing large .zip archive. Note: The QuickAppend method is new and available in the pre-release downloads, or in official releases dated after 6-October-2007.

Download Chilkat Zip ActiveX

LOCAL loZip
LOCAL lnSuccess
LOCAL lnSaveExtraPath

loZip = CreateObject('Chilkat.Zip2')

*  Any string unlocks the component for the 1st 30-days.
lnSuccess = loZip.UnlockComponent("Anything for 30-day trial")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loZip.LastErrorText)
    QUIT
ENDIF

*  The NewZip method only initializes the Zip object -- it does
*  not create or write a .zip file.
lnSuccess = loZip.NewZip("notUsed.zip")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loZip.LastErrorText)
    QUIT
ENDIF

*  Add a reference to a file.  This is the file that will
*  be added to a pre-existing .zip archive.
*  Note: this does not read or compress the file contents --
*  it simply adds a reference to the zip object.

lnSaveExtraPath = 0
lnSuccess = loZip.AppendOneFileOrDir("something.dat",lnSaveExtraPath)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loZip.LastErrorText)
    QUIT
ENDIF

*  Appends the contents of the zip object to the preExisting.zip
*  zip archive.  preExisting.zip is opened, and the files
*  referenced by this zip object are streamed in, compressed,
*  and appended to the end of the archive.
lnSuccess = loZip.QuickAppend("preExisting.zip")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loZip.LastErrorText)
    QUIT
ENDIF

=MESSAGEBOX("Success!")

*  Note: Additional files, directory trees, or in-memory data
*  can be appended by calling AppendOneFileOrDir, AppendFiles,
*  AppendString, AppendData, etc. multiple times.
*  Whatever files and/or in-memory data that are referenced by
*  this zip object will be appended to preExisting.zip when
*  QuickAppend is called.